import {
    INCREMENTCOUNT,
    DECREMENTCOUNT
} from '../constnant/countConst' //引入常量

//定义reducer的初始值
const init = {
    count: 0
}

export default function countReducer(prevStata = init, action) {
    // console.log("reducer调用了");
    // console.log(prevStata , action);

    //接受action对象的type和data
    const {
        type,
        data
    } = action;

    switch (type) {
        case INCREMENTCOUNT:
            return {
                ...init , count: prevStata.count + data
            };

        case DECREMENTCOUNT:
            return {
                ...init , count: prevStata.count - data
            }
    }

    return prevStata;
}